Communication system including antennas on substrate

ABSTRACT

A communication system includes a substrate, a plurality of antennas disposed on the substrate, and a radio frequency (RF) tag. A distance between the RF tag and at least one antenna among the plurality of antennas is detected based on a signal emitted by the RF tag and received by the at least one antenna.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation in part of application Ser. No.16/936,884 filed on Jul. 23, 2020, issued as U.S. Pat. No. 11,039,538,which is a Continuation of application Ser. No. 16/204,255 filed on Nov.29, 2018, issued as U.S. Pat. No. 10,765,007, which claims priority toKorean Patent Application No. 10-2017-0161134 filed on Nov. 29, 2017.The aforementioned applications are incorporated herein by reference intheir entireties.

TECHNICAL FIELD

The present invention relates to a communication device based on a boardfor wireless communication with an RF tag, and more particularly, to acommunication device based on a board including a plurality of antennascommunicating with an RF tag to precisely estimate the location of theRF tag. Further, the present invention relates to a safety device for aflexible circuit board, which is characterized by measuring a damageportion of a specific area of the flexible circuit board throughmeasurement on whether it is normal with a measurement or verificationsensor for an amount of current supplied to each.

RELATED ART

RF is an abbreviation of Radio Frequency and is a communication methodfor exchanging information by radiating radio frequency. As a technologyto replace the barcode that has been widely used in the past, shortrange wireless communication is attracting attention. Since short rangewireless communications may process more information than barcodes andmay transmit and receive information without touching or scanningdirectly, recently, its application range is expanding.

The short range wireless communication is used to attach a short rangewireless communication tag to target objects, and a reader reads the tagto transmit/receive information.

The tag includes a tag chip for storing information and processingsignals and an antenna unit for transmitting and receiving signals. Theantenna unit has an RF characteristic capable of transmitting andreceiving a frequency corresponding to a signal transmitted and receivedby the reader.

A flexible circuit board refers to an electronic circuit including aflexible material that may be easily bent and folded.

SUMMARY

The present disclosure provides a communication device based on a boardor a substrate including a plurality of antennas communicating with anRF tag to precisely calculate the location of the tag.

The present disclosure also provides variously activating a plurality ofantennas included in a communication device to calculate the location ofthe RF tag while minimizing power consumption.

The present disclosure also provides recognizing the bending of aflexible circuit board in a communication device.

An embodiment of the inventive concept provides a communication devicecommunicating wirelessly. The communication device includes: a controlunit configured to collectively control the communication device; apower supply unit configured to supply power to a configuration includedin the communication device based on a control of the control unit; asubstrate; and a plurality of antennas disposed on the substrate.

In an embodiment, the power supply unit may adjust an amount of currentsupplied to each of a plurality of antennas so that a detection range ofone antenna does not overlap a detection range of another antenna.

In an embodiment, the power supply unit may adjust an amount of currentsupplied to each of the plurality of antennas so that a detection rangeof one antenna may overlap a detection range of another antenna closestto the one antenna.

In an embodiment, the power supply unit may adjust an amount of currentsupplied to each of the plurality of antennas so that a detection rangeof one antenna may overlap a detection range of another antenna that isthe second closest to the one antenna.

In an embodiment, the control unit may calculate a location of an RF tagbased on an antenna for wirelessly communicating with the RF tag, and asignal strength of a signal received by the antenna from the RF tag.

In an embodiment, the plurality of antennas may be arranged in aplurality of rows and columns, wherein the power supply unit maysequentially apply power to a plurality of antennas in ascending orderof the rows, and apply power to a plurality of antennas located in thesame row in ascending order of the columns.

In an embodiment, the plurality of antennas may be arranged in aplurality of rows and columns, wherein the power supply unit may supplypower to only one antenna of two antennas disposed closest to eachother.

In an embodiment, an RF tag may be disposed on the flexible circuitboard, wherein the control unit may determine whether the flexiblecircuit board is bent based on a received signal strength received bythe plurality of antennas from the RF tag.

In an embodiment of the inventive concept, a safety device based on aflexible circuit board includes: a control unit configured tocollectively control the safety device based on the flexible circuitboard; a power supply unit configured to supply power to a configurationincluded in the safety device based on the flexible circuit board basedon a control of the control unit; and a flexible circuit board, whereina damage portion of a specific area of the flexible circuit board ismeasured through measurement on whether it is normal with a measurementor verification sensor for an amount of current supplied to each.

In an embodiment of the inventive concept, provided is a device with abuilt-in protection circuit to recognize bending in a flexible circuitboard and to prevent fire and malfunction, wherein the device with thebuilt-in protection circuit includes the device above.

In an embodiment of the inventive concept, provided is a storage mediumfor storing software to recognize bending in a flexible circuit boardand to prevent fire and malfunction, which is implemented in the deviceabove.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the inventive concept, and are incorporated in andconstitute a part of this specification. The drawings illustrateexemplary embodiments of the inventive concept and, together with thedescription, serve to explain principles of the inventive concept. Inthe drawings:

FIG. 1 shows the overall configuration of a communication deviceaccording to an embodiment;

FIG. 2 shows a plurality of antennas disposed on a control unit, a powersupply unit, and a flexible circuit board according to an embodiment;

FIG. 3 shows a plurality of antennas disposed on a control unit, a powersupply unit, and a flexible circuit board according to an embodiment;

FIG. 4 shows a plurality of antennas disposed on a control unit, a powersupply unit, and a flexible circuit board according to an embodiment;

FIG. 5 shows a plurality of antennas disposed on a control unit, a powersupply unit, and a flexible circuit board according to an embodiment;

FIG. 6 shows a plurality of antennas disposed on a control unit, a powersupply unit, and a flexible circuit board according to an embodiment;

FIGS. 7A-7C show various embodiments in which a power supply unitsupplies power to an antenna;

FIG. 8 shows a moved RF tag and an antenna 103 communicating with a tagas a flexible circuit board is bent;

FIG. 9 shows an embodiment where the communication system is implementedin a vending machine system; and

FIG. 10 shows an embodiment where the communication system isimplemented in a parking management system.

DETAILED DESCRIPTION

The foregoing and further aspects are embodied through the embodimentsdescribed with reference to the accompanying drawings. It will beunderstood that the components of each embodiment are possible invarious combinations within the embodiments as long as there is no othercomment or mutual contradiction. Furthermore, the present invention may,however, be embodied in different forms and should not be constructed aslimited to the embodiments set forth herein.

Parts not relating to description are omitted in the drawings in orderto clearly describe the present invention and like reference numeralsrefer to like elements throughout. Furthermore, when it is describedthat one comprises (or includes or has) some elements, it should beunderstood that it may comprise (or include or has) only those elements,or it may comprise (or include or have) other elements as well as thoseelements if there is no specific limitation.

In addition, throughout the specification, when a portion is referred toas being “connected” to another portion, it includes not only “directlyconnected” but also “electrically connected” with another elementtherebetween. Further, in the specification, a signal means an amount ofelectricity such as a voltage or a current.

As used herein, a “unit” refers to a “block for configuring a system ofhardware or software to be changed or pluggable”, and that is, is a unitor block that performs a specific function in hardware or software.

FIG. 1 shows the overall configuration of a communication device 100based on a flexible circuit board according to an embodiment. FIG. 2shows a plurality of antennas 103 disposed on a control unit 101, apower supply unit 102, and a flexible circuit board 104 according to anembodiment.

A communication device based on a flexible circuit board wirelesslycommunicating with an RF tag 106 includes a control unit 101 forcontrolling the communication device based on the flexible circuit boardoverall; a power supply unit 102 for supplying power to the componentsin the communication device based on the flexible circuit board based onthe control of the control unit 101; a flexible circuit board 104; and aplurality of antennas 103 disposed on the flexible circuit board 104.The power supply unit 102 adjusts the detection range of each of theplurality of antennas 103 by adjusting the amount of current supplied toeach of the plurality of antennas 103, and the detection range is withina maximum distance within which the antenna 103 receives a signal fromthe RF tag 106.

The wireless communication includes a technique for identifying anobject using a radio frequency (RF), and refers to a system that uses‘non-contact or radio frequency recognition technology’ thatautomatically recognizes, by a reader, data stored in a tag, label,card, etc. with a built-in microchip through radio frequency. Thewireless communication may include radio frequency identification(RFID), near-field communication (NFC), and the like.

An RFID system includes an RF reader that performs a reading anddecoding function and a RFID tag that stores information and exchangesdata using a protocol. The tag 106 includes a semiconductor transponderchip and an antenna, and the antenna of the tag 106 receives a radiosignal generated and propagated in the antenna 103 of a readerconfigured in an RF field. The chip of the tag 106 receives energy andtransmits pre-programmed data, and such transmission of data isperformed by modulating a part of the radio signal received at theantenna of the tag 106 and echoing it to the reader.

NFC-based tags and readers operate in active or passive communicationmode. In the active communication mode, each of the tag and the readerincludes a power supply. That is, either the tag or the reader may be areceiver for receiving data. In the passive communication mode, the tagreceives power by the electromagnetic field provided by the reader andoperates.

The antenna of the tag 106 may be categorized into an antenna for apassive tag 106 using an inductive current or a self-powered antenna foran active tag 106.

The antenna of the tag 106 is printed on a thin film material or aprinted circuit board material to be made small, and is used tocommunicate with the reader to transmit data and recognize the otherparty. In general, the antenna of the tag 106 has a characteristic inwhich the beam pattern is oriented in the vertical direction of the thinfilm or the material surface of the printed circuit board.

The control unit 101 controls the communication device based on theflexible circuit board overall. The control unit 101 is amicrocontroller or a microprocessor. That is, the control unit 101 maybe implemented by a microprocessor or a microcontroller executing aprogram stored in a memory. The control unit 101 may cause an antenna103 to generate an RF signal and radiate the RF signal therethrough,which will be described later.

The power supply unit 102 supplies power to the components of thecommunication device based on the flexible circuit board, based on thecontrol of the control unit 101.

The flexible printed circuit board 104 is a circuit board with a copperfoil on a thin insulation film having a thickness of about 10 p.m, andunlike rigid hard substrates, is thin and flexible. Although theflexible circuit board 104 is not shown in FIG. 1, the flexible circuitboard 104 is a component of the communication device 100 based on theflexible circuit board.

A plurality of antennas 103 are disposed on the flexible circuit board104. The plurality of antennas 103 may communicate with each RF tag 106.The plurality of antennas 103 may be arranged in a lattice pattern, asshown in FIG. 2. The shape in which the plurality of antennas 103 aredisposed is not limited to the lattice pattern.

The power supply unit 102 adjusts the detection range of each of theplurality of antennas 103 by adjusting the amount of current supplied toeach of the plurality of antennas 103, and the detection range is arange in which the antenna 103 receives a signal from the RF tag 106.

When the amount of current supplied by the power supply unit 102 to theantenna 103 increases, the detection range of the antenna 103 isincreased.

FIG. 3 shows a plurality of antennas 103 disposed on a control unit 101,a power supply unit 102 and a flexible circuit board 104 according to anembodiment. The antenna according to FIG. 3 detects the tag at a shortdistance. The nearest antennas are located remotely from each other anddo not overlap the detection range. Accordingly, the antennas accordingto FIG. 3 may perform multiple parallel reading without crosstalk witheach other, and the data collected for location confirmation checks thetransmission/reception signal level and has the feature of the readingpoint location information.

It is shown that in the embodiment according to FIGS. 3-6, only theantenna 103 is arranged on the flexible circuit board 104. FIG. 2 showsa plurality of antennas 103 disposed on a control unit 101, a powersupply unit 102 and a flexible circuit board 104 according to anembodiment.

The power supply unit 102 adjusts the amount of current supplied to eachof the plurality of antennas 103, so that the detection range of one ofthe antennas 103 does not overlap the detection range of the other oneof the antennas 103. Referring to FIG. 3, it may be noted that thedetection ranges of the two closest antennas 103 a and 103 b do notoverlap with each other. If the detection range overlaps, the powersupply unit 102 reduces the amount of current supplied to the antenna103 to decrease the detection range. If the distance between theboundary lines of the detection ranges is greater than the referencevalue, the power supply unit 102 increases the amount of currentsupplied to the antenna 103 to increase the detection range.

FIG. 4 shows a plurality of antennas 103 disposed on a control unit 101,a power supply unit 102 and a flexible circuit board 104 according to anembodiment. The antenna according to FIG. 3 detects the tag at a mediumdistance. The nearest antennas are arranged at a medium distance fromeach other, so that the detection range is partially overlapped.

The power supply unit 102 adjusts the amount of current supplied to eachof the plurality of antennas 103, so that the detection range of any oneof the antennas 103 overlaps the detection range of the other antenna103 closest to the one of the antennas 103. In the embodiment accordingto FIG. 3, if the power supply unit 102 supplies more current to theantenna 103 than the current supplied to the antenna 103, the detectionrange for each antenna 103 may be increased. Referring to FIG. 4, it maybe noted that the detection range of one antenna 103 a overlaps thedetection range of the two antennas 103 b and 103 c closest to theantenna 103 a.

FIG. 5 shows a plurality of antennas 103 disposed on a control unit 101,a power supply unit 102 and a flexible circuit board 104 according to anembodiment. The antenna according to FIG. 5 detects the tag at a longdistance. Two adjacent antennas are arranged close to each other. Thedetection ranges of the plurality of antennas are overlapped, so that ina sequential search, it is possible to perform a double or triple searchand a distribution diagram is generated. Collection data for locationconfirmation checks the transmission/reception signal level, checks thereading point location information, generates a reception distributiondiagram, and check a crosstalk material.

The power supply unit 102 adjusts the amount of current supplied to eachof the plurality of antennas 103, so that the detection range of any oneof the antennas 103 overlaps the detection range of the other antenna103 that is the second closest to the one of the antennas 103. In theembodiment according to FIG. 4, if the power supply unit 102 suppliesmore current to the antenna 103 than the current supplied to the antenna103, the detection range for each antenna 103 may be increased. In theembodiment according to FIG. 5, it may be noted that the detection rangeof one antenna 103 a overlaps the detection range of the two antennas103 b and 103 c closest to the antenna 103 a. Furthermore, it may benoted that the detection range of one antenna 103 a overlaps thedetection range of the two antennas 103 d that are the second closest tothe antenna 103 a.

FIG. 6 shows a plurality of antennas 103 disposed on a control unit 101,a power supply unit 102 and a flexible circuit board 104 according to anembodiment.

The control unit 101 calculates the location of the RF tag based on theantenna 103 for wirelessly communicating with the RF tag 106, and thesignal strength of the signal received by the antenna 103 from the RFtag 106.

FIG. 6 shows the RF tag 106 disposed on the flexible circuit board 104.The signal transmission range of the tag 106 is related to the powersupplied by the antenna 103. When the antenna 103 emits a strong signalas the supplied power increases, the RF tag 106 transmits a signal tothe peripheral antenna 103 based on the signal. FIG. 6 shows the signaltransmission range of the RF tag 106. If the transmission range 107 a isnarrow, only one antenna 103 a receives a signal from the RF tag 106.The control unit 101 determines that there is an RF tag 106 around theantenna 103 a.

If a transmission range 107 b is above the reference value, three ormore antennas 103 a, 103 b, 103 c, and 103 d receive signals from the RFtag 106. The control unit 101 calculates the location of the RF tag 106based on the triangulation method using the received signal strength ofthe antennas 103 a, 103 b, 103 c, and 103 d.

If a transmission range 107 c is above the reference value, three ormore antennas 103 a, 103 b, 103 c, 103 d, 103 e, and 103 f receivesignals from the RF tag 106. The control unit 101 calculates thelocation of the RF tag 106 based on the triangulation method using thereceived signal strength of the antennas 103 a, 103 b, 103 c, 103 d, 103d, 103 e, and 103 f.

FIGS. 7A-7C show various embodiments in which the power supply unit 102supplies power to the antenna 103. Referring to FIG. 7A, the pluralityof antennas 103 are arranged in a plurality of rows and columns. Thepower supply unit 102 sequentially applies power to the plurality ofantennas 103 in ascending order of the rows, and applies power to theplurality of antennas 103 located in the same row in ascending order ofthe columns. Referring to FIG. 7A, although the speed is slow withsequential search, the possibility of crosstalk is minimized.

Applying power sequentially to the plurality of antennas 103 inascending order of the rows by the power supply unit 102 means supplyingpower in the order of rows (1) to (6) in FIG. 7A. Additionally, in thesame row, power is supplied in the order of 103 a, 103 b, 103 c, and 103d. The power supply unit 102 sequentially supplies power to one antenna103, and the control unit 101 determines that the RF tag 106 is locatednear the antenna 103 having the largest received signal strength fromthe RF tag 106.

Referring to FIG. 7B, the plurality of antennas 103 are arranged in aplurality of rows and columns. The power supply unit 102 supplies powerto only one antenna 103 of the two antennas 103 disposed closest to eachother. Power is supplied to only one of the two antennas 103 a and 103 bdisposed closest to each other. That is, power is supplied to only oneantenna 103 of two arbitrary antennas 103 closest to each other in FIG.7B. The power supply unit 102 supplies power to only one antenna 103 oftwo antennas 103 closest to each other, and the control unit 101determines that the RF tag 106 is located near the antenna 103 havingthe largest received signal strength from the RF tag 106. It is possibleto estimate the location of the RF tag 106 without supplying power toall the antennas 103, thereby reducing power consumption.

Referring to FIG. 7C, the power supply unit 102 supplies power to allthe antennas 103 for a predetermined time and cuts off the power. Then,after a predetermined time, the power is supplied again. That is, thepower supply unit 102 repeatedly cuts off the power supply to all theantennas 103. The power supply unit 102 sequentially supplies power toone antenna 103, and the control unit 101 determines that the RF tag 106is located near the antenna 103 having the largest received signalstrength from the RF tag 106. Also, the control unit 101 may accuratelycalculate the location of the tag 106 through the triangulation method.Power consumption may be reduced in that power supply to the antenna 103is not always performed.

FIGS. 7B and 7C show that the possibility of crosstalk exists althoughthe search speed is fast due to multiple searches.

FIG. 8 shows the moved RF tag 106 and the antenna 103 communicating withthe tag 106 as the flexible circuit board 104 is bent.

The RF tag 106 is disposed on the flexible circuit board 104, and thecontrol unit 101 determines whether the flexible circuit board 104 isfolded based on the received signal strengths received from theplurality of antennas 103 from the RF tag 106.

In this embodiment, not only the antenna 103 but also the RF tag 106itself may be disposed on the flexible circuit board 104. When theantenna 103, which is spaced a predetermined distance from the RF tag106 in the plane on the flexible circuit board 104, receives a signalfrom the tag 106, the control unit 101 determines that the flexiblecircuit board 104 is folded. Also, the control unit 101 determines howmuch the flexible circuit board is folded based on the strength of thesignal received by the antenna 103 which is spaced a predetermineddistance from the RF tag 106.

In a communication device based on a flexible circuit board with wiredcommunication with a tag, the communication device based on the flexiblecircuit board includes a control unit for controlling the communicationdevice based on the flexible circuit board overall; a power supply unitfor supplying power to the communication device based on the control ofthe control unit based on a control of the control unit; a flexiblecircuit board; and a plurality of antennas disposed on the flexiblecircuit board. The power supply unit adjusts the amount of currentsupplied to each of the plurality of antennas to adjust the detectionrange of each of the plurality of antennas. The detection range is arange within a longest distance at which an antenna receives a signalfrom an RF tag, and an RF tag is disposed on the flexible circuit board.The control unit determines whether the flexible circuit board is foldedbased on a received signal strength received by the plurality ofantennas from the RF tag.

When the flexible circuit board is bent, it is possible to recognize thetag located in a specific area and determine the bending degree andlocation. It is possible to stop the actual electric operation byreading in real time a case where the flexible circuit board is bent ora case where the bent area is shorted.

The bending of a flexible circuit board is determined by a wirelesscommunication method, a sensor, communication disconnection, andcommunication noise measurement.

The communication system according to the present invention may beimplemented in various other applications involving an RF tag and aplurality of antennas disposed or dispersed on a substrate. Herein, theterm “substrate” may refer to any substantially planar structure, forexample, a board, a panel, a wall, a floor, or the like.

In some embodiments, as shown in FIG. 9, the communication systemaccording to the present invention may be applied to a vending machinesystem. In such embodiments, the communication system 200 may include asubstrate 204; a plurality of antennas 203 a, 203 b, 203 c, and 203 d(herein also referred to collectively as 203) disposed on the substrate204; a power supply unit 202 configured to supply power to the pluralityof antennas 203; and a control unit 201 configured to control the powersupply unit 202 to apply the power to the plurality of antennas 203 in apredetermined manner. In this embodiment, the substrate 204 of thecommunication system 200 may be logically divided into a plurality ofsections 205 a, 205 b, 205 c, 205 d, 205 e, 205 f, 205 g, 205 h, and 205i. The number of sections is not limited, and it may be varied dependingon particular applications.

When a radio frequency (RF) tag 206 is placed on a particular section ofthe substrate 204, the control unit 201 may be configured to determinethe location of the RF tag 206 with respect to the substrate 204 basedon the signals from the RF tag 206 that are received by the plurality ofantennas 203. For the determination of the location, the methodsdescribed above may be used. The location may be assigned to whichsection of the substrate 204 the RF tag 206 is placed on.

In the vending machine application, based on the section informationdetermined from the location of the RF tag 206, the control unit 201 maytransmit a payment request in an amount that is associated with thedetermined section. For example, if the RF tag 206 is determined to havebeen placed on Section 205 b, which corresponds to Product B, thecontrol unit 201 may transmit a payment request of $3.00 for Product B.

In such embodiments, the RF tag 206 may be disposed in a portabledevice, and the control unit 201 may transmit the payment request to theportable device. In response, the portable device may approve thepayment request, and subsequently, the vending machine may dispense aproduct that is associated with the section where the portable device isplaced, which is Product B in the above example. By way of example, theportable device may be implemented as any of a credit card, a debitcard, a cash card, a gift card, or a smart phone.

Referring to FIG. 10, the communication system may be applied to aparking management system. In such embodiment, the communication system300 may include a substrate 304, which is implemented as a parking lotor garage. The substrate 304 may be sectioned into a plurality ofparking spaces 305 a, 305 b, 305 c, 305 d, 305 e, 305 f, 305 g, and 305h. A plurality of antennas 303 a, 303 b, 303 c, and 303 d (herein, alsoreferred to collectively as 303) may be disposed or dispersed throughoutthe substrate 304. Similar to the foregoing embodiments, a power supplyunit 302 configured to supply power to the plurality of antennas 303 anda control unit 301 configured to control the power supply unit 302 maybe provided.

In this embodiment, the RF tag 306 may be disposed in a vehicle 307, andthe control unit 301 may be configured to determine the location of thevehicle 307 based on the location of the RF tag 306 with respect to theplurality of antennas 303. The location data may be provided to theowner of the vehicle 307 to assist identifying or finding the parkinglocation of the vehicle 307. In some embodiments, the control unit 301may be configured to also determine and record the time at which thevehicle 307 is placed at the location. The combination of the time andlocation data may be used to calculate and charge appropriate parkingfees.

In other embodiments, the communication system may be applied toagricultural systems, e.g., a hydroponic horticulture system and/orfacility. In such embodiments, the RF tag may be disposed in ahydroponic plant pot. Similar to the embodiments described above, aplurality of antennas may be utilized to determined the location of theRF tag, and thereby the location of the hydroponic plant pots. Inparticular, the control unit may be configured to store the log data oflocation changes of the RF tag. The log data of the location changes maybe utilized in managing the records of the particular hydroponic plantpot within the horticultural system and/or facility.

A communication device according to the present invention includes aplurality of antennas communicating with an RF tag to preciselycalculate the location of the tag.

It is possible to variously activate a plurality of antennas included ina communication device according to the present invention to calculatethe location of the RF tag while minimizing power consumption.

It is possible to recognize the bending of a flexible circuit board in acommunication device based on a flexible circuit board according to thepresent invention.

A communication device according to the present invention preventssignal interference caused by the overlapping of detection ranges of aplurality of antennas, thereby eliminating the erroneous recognition.

A communication device according to the present invention may accuratelycalculate the location of a wireless communicating tag.

The effects of the present invention are not limited to the effectsmentioned above, and various effects may be included within the scope ofwhat will be apparent to a person skilled in the art from the followingdescription.

In such a way, those skilled in the art will appreciate that the presentinvention may be embodied in other specific forms without departing fromthe spirit or essential characteristics thereof. Therefore, it should beunderstood that the embodiments described above are merely illustrative,and the scope is not limited. Also, the flowcharts shown in the drawingare merely the sequential steps illustrated by way of example in orderto achieve the most desirable results in practicing the presentinvention, and it is apparent that other additional steps may beprovided or some steps may be deleted.

The technical features and implementations executing this described inthis specification may be implemented in digital electronic circuits, ormay be embodied in computer software, firmware, or hardware, includingthe structures described herein, and structural equivalents thereof, ormay be embodied in a combination of one or more of these. Also,implementations executing the technical features described in thisspecification may be implemented as modules relating to computer programinstructions encoded on a type of program storage medium in order tocontrol a computer program product, that is, an operation of aprocessing system or its execution.

In such a way, this specification is not intended to limit the presentinvention by the disclosed specific term. Therefore, while the presentinvention has been particularly shown and described with reference toexemplary embodiments thereof, those of ordinary skill in the art willmade modifications, changes, and variations to the embodiments withoutdeparting from the scope of the present invention.

The scope of the present invention is defined by the appended claimsrather than the above detailed description, and all changes ormodifications derived from the meaning and range of the appended claimsand equivalents thereof are to be interpreted as being included withinthe scope of present invention.

What is claimed is:
 1. A communication system comprising: a substrate; aplurality of antennas disposed on the substrate; a power supply unitconfigured to supply power to the plurality of antennas; a control unitconfigured to control the power supply unit to apply the power to theplurality of antennas in a predetermined manner; and a radio frequency(RF) tag, wherein the control unit is configured to determine a locationof the RF tag with respect to the substrate based on a signal from theRF tag received by the plurality of antennas.
 2. The communicationsystem of claim 1, wherein the control unit is further configured to:transmit a payment request in an amount that is determined based on thelocation of the RF tag with respect to the substrate.
 3. Thecommunication system of claim 2, wherein the RF tag is disposed in aportable device, and the plurality of antennas are disposed in a vendingmachine, wherein the control unit transmits the payment request to theportable device such that the portable device approves the paymentrequest, and wherein the vending machine dispenses a product that isassociated with the location of the portable device.
 4. Thecommunication system of claim 3, wherein the portable device isimplemented as any of a credit card, a debit card, a cash card, a giftcard, or a smart phone.
 5. The communication system of claim 1, whereinthe RF tag is disposed in a vehicle, and the plurality of antennas aredisposed in a parking lot or garage, and wherein the control unit isfurther configured to determine a location of the vehicle based on thelocation of the RF tag.
 6. The communication system of claim 5, whereinthe control unit is further configured to determine time at which thevehicle is placed at the location.
 7. The communication system of claim1, wherein the control unit is further configured to: store log data oflocation changes of the RF tag.
 8. The communication system of claim 7,wherein the RF tag is disposed in a hydroponic plant pot.
 9. Thecommunication system of claim 1, wherein the plurality of antennas areprinted on a printed circuit board (PCB).
 10. The communication systemof claim 1, wherein the predetermined manner of controlling the powersupply unit includes a scanning manner, an alternating manner, anintermittent manner, or any combination thereof, wherein in the scanningmanner, the power is supplied sequentially to one antenna after anotherantenna, wherein in the alternating manner, the power is supplied toonly one antenna among two antennas that are adjacent to each other, andwherein in the intermittent manner, the power is supplied to all of theplurality of antennas with a predetermined interval.
 11. Thecommunication system of claim 1, wherein when three or more antennasamong the plurality of antennas receive signals from the RF tag, thecontrol unit is configured to determine the location of the RF tag basedon triangulation method using strengths of the signal received from theRF tag.
 12. The communication system of claim 1, wherein the location ofthe RF tag is determined based on which antenna among the plurality ofantennas receives a strongest signal from the RF tag.
 13. Thecommunication system of claim 1, wherein the power supply unit adjustsan amount of current supplied to each of the plurality of antennas toprevent a detection range of a first antenna among the plurality ofantennas from overlapping a detection range of a second antenna amongthe plurality of antennas.
 14. The communication system of claim 1,wherein the power supply unit adjusts an amount of current supplied toeach of the plurality of antennas to cause a detection range of a firstantenna among the plurality of antennas to overlap a detection range ofa second antenna among the plurality of antennas that is adjacent to thefirst antenna.
 15. The communication system of claim 1, wherein thepower supply unit adjusts an amount of current supplied to each of theplurality of antennas to cause a detection range of a first antennaamong the plurality of antennas to overlap a detection range of a secondantenna among the plurality of antennas that is two antennas apart fromthe first antenna.
 16. The communication system of claim 1, wherein theplurality of antennas are arranged in rows and columns, and wherein thepower supply unit sequentially applies power to the plurality ofantennas in ascending order of the rows, and applies power to antennasof a same row in ascending order of the columns.
 17. The communicationsystem of claim 1, wherein the plurality of antennas are arranged inrows and columns, and wherein the power supply unit supplies power toonly one antenna among two antennas disposed adjacent to each other. 18.The communication system of claim 1, wherein the power is intermittentlysupplied to all of the plurality of antennas with a predeterminedinterval.